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  • Where to find common database abbreviations in Spanish

    - by jmh_gr
    I'm doing a little pro bono work for an organization in Central America. I'm ok at Spanish and my contacts are perfectly fluent but are not techincal people. Even if they don't care what I call some fields in a database I still want to make as clean a schema as possible, and I'd like to know what some typical abbreviations are for field / variable names in Spanish. I understand abbreviations and naming conventions are entirely personal. I'm not asking for the "correct" or "best" way to abbreviate database object names. I'm just looking for references to lists of typical abbreviations that would be easily recognizable to a techincally competent native Spanish speaker. I believe I am a decent googler but I've had no luck on this one. For example, in my company (where English is the primary language) 'Date' is always shortened to 'DT', 'Code' to 'CD', 'Item' to 'IT', etc. It's easy for the crowds of IT temp workers who revolve through on various projects to figure out that 'DT' stands for 'Date', 'YR' for 'Year', or 'TN' for 'Transaction' without even having to consult the official abbreviations list.

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  • shrink ext4 partition

    - by user276851
    My question is similar to Move ext4 partition, but the challenge I couldn't figure out is how to shrink a partition from the start. So suppose originally the partition (with raid) is like this. (************** /dev/md127 ***************) After resizing, I want to achieve like this. (*** unallocated ***)(**** /dev/md127 ****) Note, I cannot use gparted, and parted does not support ext4. The commands I have tried so far, % resize2fs -p /dev/md127 1676G # <== This is good. % lvreduce -L 1676G /dev/md127 Path required for Logical Volume "md127" Please provide a volume group name Run `lvreduce --help' for more information. Failed here, I guess it may be because the underlying partition is primary and the lvreduce only works on logical? Anyway, no idea. Then after that, I am thinking to create another partition right after this one, copy the data to that partition, and remove this one, like. 1. (************** /dev/md127 ***************) 2. (**** /dev/md127 ****)(*** new partition **) 3. (*** unallocated ****)(**** /dev/md127 ****) Thanks for the help.

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  • ubuntu 12.04 LTS hangs on boot when external monitor is connected

    - by vladeta
    I have a problem with my fresh installed Ubuntu 12.04 LTS on my Dell M4600: nVidia quadro 2000M i7-2860 16GB ram 128GB SSD Dell/Samsung 750GB HDD IPS RGB laptop display When it is connected via DP++ to the external Dell U2311H monitor, it hangs on boot or when wakening from suspend. If I detach the DP cable it boots normally. I have tried all combinations that I have found, as adding to grub: "no splash", "boot=pci", "acpi=off", etc... I have also changed in nVidia X settings that external monitor is the primary one and also tried to delete monitor.xml file. There is no change it hangs each time after grub. It starts to load daemons then both screens are blank and then completely hangs with beep sound. What I discovered is if I detach the cable and wait for about 2 sec after grub starts booting and then physically connect DP cable while the Ubuntu is still booting everything works normally and I have a picture on my external screen while the laptop screen is off, just as I wanted. Do you maybe know how to solve this issue? Thank You.

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  • What technologies are needed to be a freelance web developer / designer targeting small businesses?

    - by Jason Wirth
    First off, I'm not looking for this answer: "learn PHP/MySQL, JQuery, HTML/CSS...." My background, I wear many hats, and do many things. Currently I manage investment accounts with a business partner who is also a friend. He happens to be attending business / law school perusing a joint JD and MBA. As a result, we're putting our into "coast", maintaining our current clients, but not acquiring more. Recently I've picked up some freelance graphic design / web development / online marketing side work (Photoshop, HTML/CSS, WordPress) through some personal networks. The work is enjoyable; now I'm thinking about expanding it into a larger business with these primary goals: augment my finances (I'm shooting for about $1,000-2,000 per mo.), learn new technologies, involve myself with meaningful work. As an entrepreneur I don't mind the aspects of running a business that hassle other freelancers... -- the marketing -- the billing -- etc. I'm considering targeting the small to middle market businesses and organizations where I can contribute in marketing, design, and development building projects from the ground up. Thus I'll have freedom to decide the specific technology (I won't have to work with an existing code base). What kinds of projects should I focus on? What technologies are a good fit for this style of work? For example: It might be fun to develop with Ruby on Rails. However, maybe a lot of projects would be rolling out e-commerce solutions. Thus, I should focus on PHP due to more shopping cart options, skipping ROR entirely.

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  • GRUB2 stuck at rescue console, showing "unknown filesystem" for all partitions

    - by AndiDog
    I installed Ubuntu 12.04 on my external USB drive, where I have a 700GB NTFS partition followed by the new 6GB ext4 partition and a swap partition (all primary). The GRUB MBR is also installed to the external hard disk. Since my BIOS puts the external drive as first disk when booting, I removed my internal hard disk before installation in order to avoid ordering problems. Now when I boot from the external drive, GRUB is stuck at the rescue console with the error "unknown filesystem". grub rescue> ls (hd0) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1) ls (hd0,<any of them>)/ gives me "unknown filesystem", thus also "insmod normal" GRUB doesn't seem to be able to read my Linux partition as you can see above?! How can I solve this? Additional info: bootinfoscript says (this is with the internal drive in again, but that does not make a difference): Grub2 (v1.99) is installed in the MBR of /dev/sdb and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos2)/boot/grub on this drive. sdb1: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: sdb2: __________________________________________________________________________ File system: ext4 Boot sector type: - Boot sector info: Operating System: Ubuntu 12.04 LTS Boot files: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img sdb3: __________________________________________________________________________ File system: swap Boot sector type: - Boot sector info:

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  • Are scheduled job servers the right choice for a time sensitive game engine?

    - by maple_shaft
    I am currently architecting and designing an exciting new web application that will be entering into some areas that I have very little experience in, game development. The application is not necessarily a game, but there are some very time sensitive tasks and scheduled jobs that a server will need to run to perform game related activities (Eg. New match up starts at noon every day for a 12 day tournament, updating scoreboards at 5pm every day, etc...) In the past I have typically used cron jobs with the Quartz Scheduler running within a web application server, but I know that this isn't likely a scalable solution for the truly massive userbase that management is telling me to expect (Granted they are management and are probably highly optimistic about this) and also for how important the role of these tasks are in this web application. The other important thing I want to consider is that I want to avoid SPOF (Single Point Of Failure). If the primary job server goes down, another job server should be able to successfully run the job in its place. I suppose this can be done appropriately record locking and database transactions. My question is if scheduled jobs like CRON running on a web application server are a wise design choice given the time sensitive game tasks of this application, or is there something more appropriate for running a scalable game engine parallel to the web application servers?

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  • Should I think about switching to another platform as a .Net developer? [closed]

    - by A. Karimi
    I’ve been a developer for about 10 years and I’ve almost worked on Microsoft stack. At the last several years I’ve been introduced to some good practices such as IoC and other primary design patterns. Now I feel so much comfortable using these patterns and concepts and I’m very angry why we didn’t do that earlier! They exist and used by many developers since more than 5 years ago but why I and many of my colleagues began using them a little later. As you may know Java developers are more ahead in these fields (concepts, patterns and …) than .Net developers. Am I right? Now the question is, “Why we (as .NET developers) weren’t ahead so much? Isn’t it because we are using Microsoft stack?”. I know ALT.NET but why we are trying make a closed ecosystem open and finding alternatives for Microsoft Echo Chamber, while there are natively open ecosystems like Java!? I've always liked most of the Microsoft works very much but I’m worried about this issue. I am even ask myself should I move to another platform?

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  • How can # of unique visitors be more than # of visits?

    - by Dallas
    I am confused as heck. When looking at a few individual pages, I am seeing weird results I hope someone can help explain. I am doing manual standard reports, and not creating or using a widget. For each of the two tests below, the metrics I am using are visits (not visitors) and unique visitors. I am using Page as my primary dimension and Page Title as secondary. I am filtering to include certain Pages. Example 1 - Looking at a single page... I see 731 unique visitors and 169 visits. How is this possible? Does google just flip them around for some reason? Example 2 - Looking at several pages combined... If you examine the timeline below , you can see that the numbers are all over the place. How is it possible to have more unique visitors than visits? What am I missing? I would suspect that if things were just flipped around, then I should still see one line that is always below the other line. Anyone clue me in to what may be happening here? I also notice that the visits column (just out of view) adds up to the total, but the unique visitors column clearly doesn't.

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  • Cloud Fact for Business Managers #3: Where You Data Is, and Who Has Access to It Might Surprise You

    - by yaldahhakim
    Written by: David Krauss While data security and operational risk conversations usually happen around the desk of a CCO/CSO (chief compliance and/or security officer), or perhaps the CFO, since business managers are now selecting cloud providers, they need to be able to at least ask some high-level questions on the topic of risk and compliance.  While the report found that 76% of adopters were motivated to adopt cloud apps because of quick access to software, most of these managers found that after they made a purchase decision their access to exciting new capabilities in the cloud could be hindered due to performance and scalability constraints put forth  by their cloud provider.  If you are going to let your business consume their mission critical business applications as a service, then it’s important to understand who is providing those cloud services and what kind of performance you are going to get.  Different types of departments, companies and industries will all have unique requirements so it’s key to take this also into consideration.   Nothing puts a CEO in a bad mood like a public data breach or finding out the company lost money when customers couldn’t buy a product or service because your cloud service provider had a problem.  With 42% of business managers having seen a data security breach in their department associated directly with the use of cloud applications, this is happening more than you think.   We’ve talked about the importance of being able to avoid information silos through a unified cloud approach and platform.  This is also important when keeping your data safe and secure, and a key conversation to have with your cloud provider.  Your customers want to know that their information is protected when they do business with you, just like you want your own company information protected.   This is really hard to do when each line of business is running different cloud application services managed by different cloud providers, all with different processes and controls.   It only adds to the complexity, and the more complex, the more risky and the chance that something will go wrong. What about compliance? Depending on the cloud provider, it can be difficult at best to understand who has access to your data, and were your data is actually stored.  Add to this multiple cloud providers spanning multiple departments and it becomes very problematic when trying to comply with certain industry and country data security regulations.  With 73% of business managers complaining that having cloud data handled externally by one or more cloud vendors makes it hard for their department to be compliant, this is a big time suck for executives and it puts the organization at risk. Is There A Complete, Integrated, Modern Cloud Out there for Business Executives?If you are a business manager looking to drive faster innovation for your business and want a cloud application that your CIO would approve of, I would encourage you take a look at Oracle Cloud.  It’s everything you want from a SaaS based application, but without compromising on functionality and other modern capabilities like embedded business intelligence, social relationship management (for your entire business), and advanced mobile.  And because Oracle Cloud is built and managed by Oracle, you can be confident that your cloud application services are enterprise-grade.  Over 25 Million users and 10 thousands companies around the globe rely on Oracle Cloud application services everyday – maybe your business should too.  For more information, visit cloud.oracle.com. Additional Resources •    Try it: cloud.oracle.com•    Learn more: http://www.oracle.com/us/corporate/features/complete-cloud/index.html•    Research Report: Cloud for Business Managers: The Good, the Bad, and the Ugly

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  • F# Objects &ndash; Part 3 &ndash; it&rsquo;s time to overload&hellip;

    - by MarkPearl
    Okay, some basic examples of overloading in F# Overloading Constructors Assume you have a F# object called person… type Person (firstname : string, lastname : string) = member v.Fullname = firstname + " " + lastname   This only has one constructor. To add additional constructors to the object by explicitly declaring them using the method member new. type Person (firstname : string, lastname : string) = new () = Person("Unknown", "Unknown") member v.Fullname = firstname + " " + lastname   In the code above I added another constructor to the Person object that takes no parameters and then refers to the primary constructor. Using the same technique in the code below I have created another constructor that accepts only the firstname as a parameter to create an object. type Person (firstname : string, lastname : string) = new () = Person("Unknown", "Unknown") new (firstname : string) = Person(firstname, "Unknown") member v.Fullname = firstname + " " + lastname   Overloading Operators So, you can overload operators of objects in F# as well… let’s look at example code… type Person(name : string) = member v.name = name static member (+) (person1 : Person , person2 : Person) = Person(person1.name + " " + person2.name)   In the code above we have overloaded the “+” operator. Whenever we add to Person objects together, it will now create a new object with the combined names…

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  • Information I need to know as a Java Developer [on hold]

    - by Woy
    I'm a java developer. I'm trying to get more knowledge to become a better programmer. I've listed a number of technologies to learn. Instead of what I've listed, what technologies would you suggest to learn as well for a Junior Java Developer? I realize, there's a lot of things to study. Java: - how a garbage collector works - resource management - network programming - TCP/IP HTTP - transactions, - consistency: interfaces, classes collections, hash codes, algorithms, comp. complexity concurrent programming: synchronizing, semafores steam management metability: thread-safety byte code manipulations, reflections, Aspect-Oriented Programming as base to understand frameworks such as Spring etc. Web stack: servlets, filters, socket programming Libraries: JDK, GWT, Apache Commons, Joda-Time, Dependency Injections: Spring, Nano Tools: IDE: very good knowledge - debugger - profiler - web analyzers: Wireshark, firebugs - unit testing SQL/Databases: Basics SELECTing columns from a table Aggregates Part 1: COUNT, SUM, MAX/MIN Aggregates Part 2: DISTINCT, GROUP BY, HAVING + Intermediate JOINs, ANSI-89 and ANSI-92 syntax + UNION vs UNION ALL x NULL handling: COALESCE & Native NULL handling Subqueries: IN, EXISTS, and inline views Subqueries: Correlated ITH syntax: Subquery Factoring/CTE Views Advanced Topics Functions, Stored Procedures, Packages Pivoting data: CASE & PIVOT syntax Hierarchical Queries Cursors: Implicit and Explicit Triggers Dynamic SQL Materialized Views Query Optimization: Indexes Query Optimization: Explain Plans Query Optimization: Profiling Data Modelling: Normal Forms, 1 through 3 Data Modelling: Primary & Foreign Keys Data Modelling: Table Constraints Data Modelling: Link/Corrollary Tables Full Text Searching XML Isolation Levels Entity Relationship Diagrams (ERDs), Logical and Physical Transactions: COMMIT, ROLLBACK, Error Handling

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  • Multichannel Digital Engagement: Find Out How Your Organization Measures Up

    - by Michael Snow
    This article was originally published in the September 2013 Edition of the Oracle Information InDepth Newsletter ORACLE WEBCENTER EDITION Thanks to mobile and social technologies, interactive online experiences are now commonplace. Not only that, they give consumers more choices, influence, and control than ever before. So how can you make your organization stand out? The key building blocks for delivering exceptional cross-channel digital experiences are outlined below. Also, a new assessment tool is available to help you measure your organization's ability to deliver such experiences. A clearly defined digital strategy. The customer journey is growing increasingly complex, encompassing multiple touchpoints and channels. It used to be easy to map marketing efforts to specific offline channels; for example, a direct mail piece with an offer to visit a store for a discounted purchase. Now it is more difficult to cultivate and track such clear cause-and-effect relationships. To deliver an integrated digital experience in this more complex world, organizations need a clearly defined and comprehensive digital marketing strategy that is backed up by an integrated set of software, middleware, and hardware solutions. Strong support for business agility and speed-to-market. As both IT and marketing executives know, speed-to-market and business agility are key to competitive advantage. That means marketers need solutions to support the rapid implementation of online marketing initiatives—plus the flexibility to adapt quickly to a changing marketplace. And IT needs tools with the performance, scalability, and ease of integration to support marketing efforts. Both teams benefit when business users are empowered to implement marketing initiatives on their own, with minimal IT intervention. The ability to deliver relevant, personalized content. Delivering a one-size-fits-all online customer experience is no longer acceptable. Customers expect you to know who they are, including their preferences and past relationship with your brand. That means delivering the most relevant content from the moment a visitor enters your site. To make that happen, you need a powerful rules engine so that marketers and business users can easily define site visitor segments and deliver content accordingly. That includes both implicit targeting that is based on the user’s behavior, and explicit targeting that takes a user’s profile information into account. Ideally, the rules engine can also intelligently weight recommendations when multiple segments apply to a specific customer. Support for social interactivity. With the advent of Facebook and LinkedIn, visitors expect to participate in and contribute to your web presence—and share their experience on their own social networks. That requires easy incorporation of user-generated content such as comments, ratings, reviews, polls, and blogs; seamless integration with third-party social networking sites; and support for social login, which helps to remove barriers to social participation. The ability to deliver connected, multichannel experiences that include powerful, flexible mobile capabilities. By 2015, mobile usage is projected to surpass that of PCs and other wired devices. In other words, mobile is an essential element in delivering exceptional online customer experiences. This requires the creation and management of mobile experiences that are optimized for delivery to the thousands of different devices that are in use today. Just as important, organizations must be able to easily extend their traditional web presence to the mobile channel and deliver highly personalized and relevant multichannel marketing initiatives while also managing to minimize the time and effort required to manage mobile sites. Are you curious to know how your organization measures up when it comes to delivering an engaging, multichannel digital experience? If so, take this brief, 15-question online assessment and see how your organization scores in the areas of digital strategy, digital agility, relevance and personalization, social interactivity, and multichannel experience.

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  • MySQL Server 5.6 default my.cnf and my.ini

    - by user12626240
    We've introduced a default my.cnf / my.ini file for MySQL Server that you can now see in the 5.6.8 release candidate: # For advice on how to change settings please see # http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html [mysqld] # Remove leading # and set to the amount of RAM for the most important data # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%. # innodb_buffer_pool_size = 128M   # Remove leading # to turn on a very important data integrity option: logging # changes to the binary log between backups. # log_bin   # These are commonly set, remove the # and set as required. # basedir = ..... # datadir = ..... # port = ..... # socket = ..... # server_id = .....   # Remove leading # to set options mainly useful for reporting servers. # The server defaults are faster for transactions and fast SELECTs. # Adjust sizes as needed, experiment to find the optimal values. # join_buffer_size = 128M # sort_buffer_size = 2M # read_rnd_buffer_size = 2M   sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES    There is also a template file called my-default.cnf or my-default.ini that has these lines near the start: # *** DO NOT EDIT THIS FILE. It's a template which will be copied to the # *** default location during install, and will be replaced if you # *** upgrade to a newer version of MySQL.   On Linux systems, the mysql_install_db command will copy the template file to the final location, where the server will read and use the file, removing the extra three lines. On Windows, the installer will create extra settings based on the answers you gave during installation. Neither will overwrite an existing my.cnf or my.ini file. The only initially active setting here is to change the value of  sql_mode from the server default of NO_ENGINE_SUBSTITUTION to NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES. This strict mode changes warnings for some non-standard behaviour into errors. This can cause applications which rely on the non-standard things, like dates that aren't valid, to lose data. If we had just changed the server default, the new setting would affect all servers that lack an explicit sql_mode setting, including those where strict mode is harmful. So we did it in the default file instead because that will only affect new server installations. You should expect that in our next version after 5.6, the server default will include STRICT_TRANS_TABLES. Our Windows installer and some of our connectors already use STRICT_TRANS_TABLES by default. Strict has been our preferred setting for many years and it is good to see some development platforms are using it. If you need the old behaviour, just remove the STRICT_TRANS_TABLES setting. If you do this, please also ask your application provider to make it unnecessary. They can do that by setting the session sql_mode setting in their own connections, so the rest of the applications using the server don't have to have an undesirable default. We've kept this file as small as possible because we found that our old files were too big and confused people. We've also now removed the old my-huge and related example files. One key part of this is the link to the documentation, where we will provide an introduction to some key settings. We'd like to hear your feedback on settings that will benefit most users or are most important to call out for existing users. Please do that by commenting here or if you prefer by adding comments to this bug report.

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  • Partitions for dual boot install with Windows

    - by Tim
    Following is the layout of the current partitions of my single hard drive viewed from Windows 7: C: has Windows 7 system files and my personal data; Q: for Lenovo recovery; SYSTEM_DRV: for Windows boot files; My goals are: to create another partition D: for my personal data, and dedicate C: for Windows system files and applications only. to install Ubuntu alongside Windows. D: will be shared between the two OSes. My questions are: Is it correct that the free space generated from shrinking C: will only be able to create an extended partition, since there are already 3 primary partitions? So must D: be one logical partition on the extended partition, just as the partitions for Ubuntu will be? Will this be bad sometime? If yes, other better solutions? What are the good utilities to accomplish the partition tasks? Can Ubuntu installer solely handle them? Or better to have some of the jobs done in Windows with some recommended softwares? Thanks and regards!

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  • Dual displays not working - NVidia - Ubuntu 12.04 - Second Monitor - Two Screens

    - by user75105
    Graphics Card: NVidia 460 GTX. Driver: NVIDIA accelerated graphics driver (version current) I have one DVI monitor, an old Dell LCD from 2005, and one VGA monitor, an Asus ML238H from 2010 whose HDMI port broke. The Asus is plugged into my graphics card's primary monitor slot and is the better monitor even though it is VGA but my computer defaults to the Dell. This happens when I boot as well; the loading screens, the motherboard brand image, etc. are all displayed on the Dell monitor until Windows loads. Then both monitors work. The same thing happened when I booted up Ubuntu 12.04 but I did not see the second monitor when the log-in screen popped up, nor did I when I logged in. I went to System Settings/Displays and my Asus monitor is not an option. I clicked Detect Displays and the Asus is not detected. I looked at the other questions regarding NVIDIA drivers and recalled my problems with Ubuntu a few years ago and decided to check the driver. I went to Additional Drivers to install the proprietary driver and it looks like it's installed and active but I'm still having this problem. There is another driver option, the post-release NVIDIA driver, but that does not fix the problem either. Also, under System Details/Graphics the graphics device is listed as Unknown, which might indicate that it is using an open source generic driver and not the proprietary NVidia driver. But under Additional Drivers it says that I am using the NVidia driver. Any help is appreciated.

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  • Is it okay to use a language that isn't supported by your company for some tasks?

    - by systempuntoout
    I work for a company that supports several languages: COBOL, VB6, C# and Java. I use those languages for my primary work, but I often find myself to coding some minor programs (e.g. scripts) in Python because I found it to be the best tool for that type of task. For example: An analyst gives me a complex CSV file to populate some DB tables, so I would use Python to parse it and create a DB script. What's the problem? The main problem I see is that a few parts of these quick & dirty scripts are slowly gaining importance and: My company does not support Python They're not version controlled (I back them up in another way) My coworkers do not know Python The analysts have even started referencing them in email ("launch the script that exports..."), so they are needed more often than I initially thought. I should add that these scripts are just utilities that are not part of the main project; they simply help to get trivial tasks done in less time. For my own small tasks they help a lot. In short, if I were a lottery winner to be in a accident, my coworkers would need to keep the project alive without those scripts; they would spend more time in fixing CSV errors by hand for example. Is this a common scenario? Am I doing something wrong? What should I do?

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  • From the Coalface - 3 - Work as hard as you can to be as lazy as you can!

    - by TATWORTH
    The saga of the Change Log A recent conversation reminded me of the need for change logs within a database, to record when various change scripts were run. Creating such the required table is simple. A typical table for this consists of: Id - identity Integer primary key ChangeFileName - NVARCHAR(128) to hold the name of the file run. DateAdded - DateTime non-null with default value of getutcdate() Purpose - NVARCHAR(128) Rerunnable - Bit non-null default 0. By good design of the table only two data values normally need to be supplied. Two stored procedures, one for inserting data and one to list in reverse sequence the log complete the database essentials. The complete implementation can be found in the CommonData solution at http://CommonData.CodePlex.Com By including a call the add Change Log stored procedure, each script can log its name and purpose for posterity. The scripts that were applied to say the UAT system and their sequence of application can be readily identified for running on the Live system. Formatting XML XML is often produced as one continous string with no embedded CR/LF. To get it into human readable form, open it in visual studio, swap to another tab and back and click the format document button. The XML will then be nicely formatted!

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  • What is involved with writing a lobby server?

    - by Kira
    So I'm writing a Chess matchmaking system based on a Lobby view with gaming rooms, general chat etc. So far I have a working prototype but I have big doubts regarding some things I did with the server. Writing a gaming lobby server is a new programming experience to me and so I don't have a clear nor precise programming model for it. I also couldn't find a paper that describes how it should work. I ordered "Java Network Programming 3rd edition" from Amazon and still waiting for shipment, hopefully I'll find some useful examples/information in this book. Meanwhile, I'd like to gather your opinions and see how you would handle some things so I can learn how to write a server correctly. Here are a few questions off the top of my head: (may be more will come) First, let's define what a server does. It's primary functionality is to hold TCP connections with clients, listen to the events they generate and dispatch them to the other players. But is there more to it than that? Should I use one thread per client? If so, 300 clients = 300 threads. Isn't that too much? What hardware is needed to support that? And how much bandwidth does a lobby consume then approx? What kind of data structure should be used to hold the clients' sockets? How do you protect it from concurrent modification (eg. a player enters or exists the lobby) when iterating through it to dispatch an event without hurting throughput? Is ConcurrentHashMap the correct answer here, or are there some techniques I should know? When a user enters the lobby, what mechanism would you use to transfer the state of the lobby to him? And while this is happening, where do the other events bubble up? Screenshot : http://imageshack.us/photo/my-images/695/sansrewyh.png/

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  • Kloxo - Use third party nameserver

    - by LePhleg
    Here's my case: I got my domain from a registrar. I got my VPS up from a provider who also offers free DNS hosting, on their own server (separately from my VPS, IP:111.111.111.111). So I got these third-party nameservers, lets name them: ns1.provider.com ns2.provider.com and pointed my domain registrar to them. I let it propagate for 24 hours so I believe its ok. (if I ping my domain I get the IP for these nameservers - 111.111.111.111) Afterwards I headed to my providers cPanel (the one they gave me for the DNS hosting service) and changed the default A Record IP from 111.111.111.111 to the IP associated with my VPS (IP:222.222.222.222). The last step, as I see it, is to configure my VPS via Kloxo panel and add the domain. Can someone guide me how can I achieve that? Is it just enough to create a new DNS Template and add as Primary DNS "ns1.provider.com" and Secondary DNS "ns2.provider.com"? Every tutorial I found is using Kloxo to create local nameservers on the same VPS which is something I want to avoid to save resources..

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  • Package Manager cannot access repositories but internet is working

    - by kazman
    I am currently at a conference in another country and my package manager cannot access repositories. My internet is working fine and I can ping the repositories or go to them in a browser, but package manager fails to access them. If I sudo apt-get update it throws Something wicked happened resolving 'wwwproxy:3128' (-5 - No address associated with hostname) (or Ign's). This proxy corresponds to my proxy at my office back at home, but I have disabled proxy in the package manager. Scanning for best repository doesn't work either, it doesn't manage to connect to any. I have searched for this online and have checked things about my apt.conf file. My apt.conf contains: Acquire::http::proxy "http://wwwproxy:3128/"; Acquire::https::proxy "https://wwwproxy:3128/"; Acquire::ftp::proxy "ftp://wwwproxy:3128/"; Acquire::socks::proxy "socks://wwwproxy:3128/"; If I remove apt.conf (or replace with blank), it makes no difference. I don't see that it should since I am connecting directly (and have set it so in my network options in Package manager network settings) I have also tried some things with resolv.conf (changing name address to primary and secondary dns) to no avail. (im not sure if this would help, following other advice) I am running 12.04. (I wrote this very quickly and wrote down everything I have tried to possibly shorten the troubleshooting process, have very limited time between lectures and need this sorted asap, my apologies)

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  • Is full partition encryption the only sure way to make Ubuntu safe from external access?

    - by fred.bear
    (By "external access", I mean eg. via a Live CD, or another OS on the same dual-boot machine) A friend wants to try Ubuntu. He's fed up with Vista grinding to a crawl (the kids? :), so he likes the "potential" security offered by Ubuntu, but because the computer will be multi-booting Ubuntu (primary) and 2 Vistas (one for him, if he ever needs it again, and the other one for the kids to screw up (again). However, he is concerned about any non-Ubuntu access to the Ubuntu partitions (and also to his Vista partition)... I believe TrueCrypt will do the job for his Vista, but I'd like to know what the best encryption system for Ubuntu is... If TrueCrypt works for Ubuntu, it may be the best option for him, as it would be the same look and feel for both. Ubuntu will be installed with 3 partitions; 1) root 2) home 3) swap.. Will Ubuntu's boot loader clash with TrueCrypt's encrypted partition? PS.. Is encryption a suitable solution?

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  • Dual displays not working - NVidia - Ubuntu 12.4

    - by user75105
    Graphics Card: NVidia 460 GTX. Driver: NVIDIA accelerated graphics driver (version current) I have one DVI monitor, an old Dell LCD from 2005, and one VGA monitor, an Asus ML238H from 2010 whose HDMI port broke. The Asus is plugged into my graphics card's primary monitor slot and is the better monitor even though it is VGA but my computer defaults to the Dell. This happens when I boot as well; the loading screens, the motherboard brand image, etc. are all displayed on the Dell monitor until Windows loads. Then both monitors work. The same thing happened when I booted up Ubuntu 12.4 but I did not see the second monitor when the log-in screen popped up, nor did I when I logged in. I went to System Settings/Displays and my Asus monitor is not an option. I clicked Detect Displays and the Asus is not detected. I looked at the other questions regarding NVIDIA drivers and recalled my problems with Ubuntu a few years ago and decided to check the driver. I went to Additional Drivers to install the proprietary driver and it looks like it's installed and active but I'm still having this problem. There is another driver option, the post-release NVIDIA driver, but that does not fix the problem either. Also, under System Details/Graphics the graphics device is listed as Unknown, which might indicate that it is using an open source generic driver and not the proprietary NVidia driver. But under Additional Drivers it says that I am using the NVidia driver. Any help is appreciated.

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  • Webcast On-Demand: Building Java EE Apps That Scale

    - by jeckels
    With some awesome work by one of our architects, Randy Stafford, we recently completed a webcast on scaling Java EE apps efficiently. Did you miss it? No problem. We have a replay available on-demand for you. Just hit the '+' sign drop-down for access.Topics include: Domain object caching Service response caching Session state caching JSR-107 HotCache and more! Further, we had several interesting questions asked by our audience, and we thought we'd share a sampling of those here for you - just in case you had the same queries yourself. Enjoy! What is the largest Coherence deployment out there? We have seen deployments with over 500 JVMs in the Coherence cluster, and deployments with over 1000 JVMs using the Coherence jar file, in one system. On the management side there is an ecosystem of monitoring tools from Oracle and third parties with dashboards graphing values from Coherence's JMX instrumentation. For lifecycle management we have seen a lot of custom scripting over the years, but we've also integrated closely with WebLogic to leverage its management ecosystem for deploying Coherence-based applications and managing process life cycles. That integration introduces a new Java EE archive type, the Grid Archive or GAR, which embeds in an EAR and can be seen by a WAR in WebLogic. That integration also doesn't require any extra WebLogic licensing if Coherence is licensed. How is Coherence different from a NoSQL Database like MongoDB? Coherence can be considered a NoSQL technology. It pre-dates the NoSQL movement, having been first released in 2001 whereas the term "NoSQL" was coined in 2009. Coherence has a key-value data model primarily but can also be used for document data models. Coherence manages data in memory currently, though disk persistence is in a future release currently in beta testing. Where the data is managed yields a few differences from the most well-known NoSQL products: access latency is faster with Coherence, though well-known NoSQL databases can manage more data. Coherence also has features that well-known NoSQL database lack, such as grid computing, eventing, and data source integration. Finally Coherence has had 15 years of maturation and hardening from usage in mission-critical systems across a variety of industries, particularly financial services. Can I use Coherence for local caching? Yes, you get additional features beyond just a java.util.Map: you get expiration capabilities, size-limitation capabilities, eventing capabilites, etc. Are there APIs available for GoldenGate HotCache? It's mostly a black box. You configure it, and it just puts objects into your caches. However you can treat it as a glass box, and use Coherence event interceptors to enhance its behavior - and there are use cases for that. Are Coherence caches updated transactionally? Coherence provides several mechanisms for concurrency control. If a project insists on full-blown JTA / XA distributed transactions, Coherence caches can participate as resources. But nobody does that because it's a performance and scalability anti-pattern. At finer granularity, Coherence guarantees strict ordering of all operations (reads and writes) against a single cache key if the operations are done using Coherence's "EntryProcessor" feature. And Coherence has a unique feature called "partition-level transactions" which guarantees atomic writes of multiple cache entries (even in different caches) without requiring JTA / XA distributed transaction semantics.

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  • What is meant by "no password set" for root account (and otthers)?

    - by MMA
    Several years back, we were more accustomed to changing to the root account using the su command. First, we switched to the root account, and then executed those root commands. Now we are more accustomed to using the sudo command. But we know that the root account is there. We can readily find the home directory of user root. $ ls -ld /root/ drwx------ 18 root root 4096 Oct 22 17:21 /root/ Now my point is, it is stated that "the root password in Ubuntu is left unset". Please see the answers to this question. Most of the answers have something to this effect in the first paragraph. One or two answers further state that "the account is left disabled". Now my (primary) questions are, What is meant by an unset password? Is it blank? Is it null? Or something else more cryptic? How does the account becomes enabled once I set password for it? (sudo password root) In order get a better understanding, I checked the /etc/shadow file. Since I have already set a password for the root account, I can no longer see what is there (encrypted password). So, I created another account and left it disabled. The corresponding entry in the /etc/shadow file is, testpassword:!:16020:0:99999:7::: Now perhaps my above queries need to be changed to, what does an ! in password field mean? Other encrypted passwords are those very long cryptic strings. How come this encrypted form is only one character long? And does an account become disabled if I put an ! in the (encrypted) password field?

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  • Wireless does not work 12.10

    - by superkoop
    My primary issue is that my wireless does not work after I installed 12.10. The output to rfkill list all: 5: hci0: Bluetooth Soft blocked: no Hard blocked: no The output to lshw -class network is: *-network description: Ethernet interface product: 88E8040 PCI-E Fast Ethernet Controller vendor: Marvell Technology Group Ltd. physical id: 0 bus info: pci@0000:09:00.0 logical name: eth0 version: 12 serial: 00:21:9b:d6:46:51 size: 100Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.30 duplex=full ip=192.168.1.102 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s resources: irq:44 memory:fe8fc000-fe8fffff ioport:de00(size=256) *-network description: Network controller product: BCM4312 802.11b/g LP-PHY vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:0b:00.0 version: 01 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list configuration: driver=b43-pci-bridge latency=0 resources: irq:17 memory:fe7fc000-fe7fffff The output to lspci -nn for the pertinent information is: 0b:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g LP-PHY [14e4:4315] (rev 01) Thus, it seems the solution would be to run: sudo apt-get install linux-headers-generic sudo apt-get install --reinstall bcmwl-kernel-source sudo modprobe wl However, I do not currently have access to an ethernet connection, as I am currently only able to use verizon wireless 3g internet. Thus, is there a way to set up ICS with a Vista machine so that I can access the internet by using the Vista machine as the host? Or, is it possible to fix this by downloading the important packages in vista and moving them to ubuntu via USB drive?

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